Systems and methods for wind tunnel operation

ABSTRACT

A system for monitoring a model in a wind tunnel is provided. The system includes a plurality of sensors attached to a model in a wind tunnel. Each sensor of the plurality of sensors is configured to measure an attribute of the model. The system also includes a computing device in communication with the plurality of sensors. The computing device is programmed to receive a plurality of signals from the plurality of sensors, store a first threshold and a second threshold based on normalized alarm limits associated with at least one of the plurality of sensors, analyze the plurality of signals based, at least in part, on the first threshold and the second threshold, determine that a potentially negative condition is occurring based on the analysis, and alert a user to the potentially negative condition.

BACKGROUND

The field of the present disclosure relates generally to wind tunneloperation, and, more specifically, to monitoring and ensuring the safetyof a model in a wind tunnel environment.

Aircraft are extensively tested throughout all stages of development.One type of testing is through the use of wind tunnels. In many cases, ascale model of the aircraft is placed on a frame in a wind tunnel andsubjected to a variety of conditions. These conditions may causecatastrophic responses from the models. In some cases, these responsesoccur in less time than an operator can respond. In some of these cases,the catastrophic responses may cause significant damage to at least oneof the model and the wind tunnel. Both the models and the wind tunnelsare expensive. There is a need for a system for preventing damage toboth the models and the wind tunnels during operation.

BRIEF DESCRIPTION

In one aspect, a system for monitoring a model in a wind tunnel isproved. The system includes a plurality of sensors attached to a modelin a wind tunnel. Each sensor of the plurality of sensors is configuredto measure an attribute of the model. The system also includes acomputing device in communication with the plurality of sensors. Thecomputing device includes a processor in communication with a memory.The computing device is programmed to receive a plurality of signalsfrom the plurality of sensors. The plurality of signals representmeasurements of the attributes of the model. The computing device isalso programmed to store a first threshold and a second threshold basedon normalized alarm limits associated with at least one of the pluralityof sensors, analyze the plurality of signals based, at least in part, onthe first threshold and the second threshold, determine that apotentially negative condition is occurring based on the analysis, andalert a user to the potentially negative condition.

In another aspect, a wind tunnel structural health monitor (WTSHM)computer device for monitoring a model in a wind tunnel is provided. TheWTSHM computer device includes a processor in communication with amemory. The processor is programmed to receive a plurality of signalsfrom a plurality of sensors. Each sensor of the plurality of sensors isconfigured to measure an attribute of a model in the wind tunnel. Theplurality of signals represent measurements of the attributes of themodel. The processor is also programmed to store a first threshold and asecond threshold based on normalized alarm limits associated with atleast one of the plurality of sensors, analyze the plurality of signalsbased, at least in part, on the first threshold and the secondthreshold, determine that a potentially negative condition is occurringbased on the analysis, and alert a user to the potentially negativecondition.

In yet another aspect, a method for monitoring a model in a wind tunnelis provided. The method is implemented using a wind tunnel structuralhealth monitor (WTSHM) computer device. The WTSHM computer deviceincludes a processor in communication with a memory. The method includesreceiving a plurality of signals from a plurality of sensors. Eachsensor of the plurality of sensors is configured to measure an attributeof a model in the wind tunnel. The plurality of signals representmeasurements of the attributes of the model. The method also includesstoring a first threshold and a second threshold based on normalizedalarm limits associated with at least one of the plurality of sensors,analyzing the plurality of signals based, at least in part, on the firstthreshold and the second threshold, determining that a potentiallynegative condition is occurring based on the analysis, and alerting auser to the potentially negative condition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an example overview of a windtunnel environment in accordance with one embodiment of the presentdisclosure.

FIG. 2 is a simplified block diagram of an example system for monitoringa model in the wind tunnel environment shown in FIG. 1.

FIG. 3 illustrates an example configuration of a client computer deviceshown in FIG. 2, in accordance with one embodiment of the presentdisclosure.

FIG. 4 illustrates an example configuration of the server system shownin FIG. 2, in accordance with one embodiment of the present disclosure.

FIG. 5 illustrates an example graph of monitored sensor data from thesystem shown in FIG. 2 during operation of the wind tunnel environmentshown in FIG. 1.

FIG. 6 is a flowchart illustrating an example of a process of monitoringa model in the wind tunnel environment shown in FIG. 1 using the systemshown in FIG. 2.

FIG. 7 is illustrates an example graph of a modified Goodman diagram ofmonitored sensor data from the system shown in FIG. 2 during operationof the wind tunnel environment shown in FIG. 1.

FIG. 8 is a diagram of components of one or more example computingdevices that may be used in the system shown in FIG. 2.

DETAILED DESCRIPTION

The implementations described herein relate to systems and methods forwind tunnel operation, and, more specifically, to monitoring andensuring the safety of a model in a wind tunnel environment. Morespecifically, a wind tunnel structural health monitor (“WTSHM”) computerdevice (also known as a WTSHM server), provides a communicationinterface between a plurality of sensors attached to an aircraft modelin a wind tunnel and the wind tunnel itself. The WTSHM computer deviceanalyzes the conditions monitored by the sensor, determines when apotentially negative condition occurs, alerts a user of the potentiallynegative condition, and potentially modifies the operation of the windtunnel in response to the potentially negative condition.

In the example embodiment, the WTSHM server receives a plurality ofsignals from a plurality of sensors attached to an aircraft model in awind tunnel. The plurality of signals represents data about attributesof the aircraft model based on the conditions in the wind tunnel. TheWTSHM server stores a first threshold and a second threshold. In theexample embodiment, the first threshold is a warning threshold and thesecond threshold is an alert threshold. In the example embodiment, thewarning threshold and the alert threshold are set by a user. In theexample embodiment, the alert threshold is at 100% and the warningthreshold is below 100% and varies based on the channel.

In the example embodiment, the WTSHM server analyzes the plurality ofsignals based on the warning threshold and the alert threshold. TheWTSHM server determines that a potentially negative condition isoccurring based on the analysis. The WTSHM server alerts the user to thepotentially negative condition.

In the example embodiment, the WTSHM server analyzes the plurality ofsignals in comparison to the warning threshold and the alert threshold.In the example embodiment, the WTSHM server normalizes the sensor datafor each channel into a percentage based on preset alarm values. In someembodiments, a channel represents a single sensor. In other embodiments,a channel may represent a plurality of sensors. For example, the WTSHMserver may receive sensor data from three strain sensors on the leftwing of the aircraft model. The WTSHM server may combine and preprocessthe data from the three sensors into channel A. The WTSHM servercompares channel A to the warning threshold and the alert threshold. Forexample, if the combined sensor data in channel A is below boththresholds, the WTSHM server does not trigger an alarm and continues tomonitor the channel.

In the case of channel B where the warning threshold is at 60%, theWTSHM server determines that the normalized output of channel B is over60% which is over warning threshold for that channel. The WTSHM serveralerts a user by initiating a short alarm. The alarm may be at least oneof a visual alarm, such as a flash of color on display screen, and ashort audible alarm, such as a squawk or blat sound.

If the WTSHM server determines that the warning threshold for channel Bhas been exceeded a predetermined number of times in a predeterminedperiod of time, such as three times in 0.5 seconds, the WTSHM serverinitiates a warning alarm. The warning alarm includes at least one of avisual alarm and an audible alarm. In the example embodiment, thepredetermined number and predetermined period of time are set by theuser. The WTSHM server stores the plurality of signals received from thesensor(s) associated with channel B for a predetermined period of timebefore and after the warning alarm was initiated. This predeterminedperiod of time may be stored as delay data. In the some embodiments, theWTSHM server receives a plurality of signals and the plurality ofsignals include a large amount of data. To save storage space, the WTSHMserver stores the data from the signals in a circular buffer such thatold data is written over after a period of time. This period of time maybe based on the predetermined period of time. For example, where theWTSHM server stores 5 seconds of data before and after an alarm wastriggered, the circular buffer may contain 13 seconds of data at a timeto ensure that the needed data has been stored. In the exampleembodiment, the WTSHM server stores the plurality of signals in adatabase, where the database is located remotely from the WTSHM server.The WTSHM server further stores the plurality of signals with a warningtag for future analysis. In some embodiments, the WTSHM server alsostores the tunnel conditions, the power spectral density of channels,and any bookmarks associated with the power spectral density for thetime before and after the alarm was triggered.

The WTSHM server also initiates a warning alarm if the WTSHM serverdetermines that the warning threshold has been exceeded by at least halfof the distance between the warning threshold and the alert threshold.For example, if a channel has the warning threshold at 60% and the alertthreshold is at 100%, a warning alarm would be initiated if the channeloutput reaches or exceeds 80%.

When the WTSHM server determines that the alert threshold has beenexceeded, the WTSHM server initiates an alert alarm. The alert alarmincludes at least one of a visual alarm and an audible alarm. In theexample embodiment, the predetermined number and predetermined period oftime are set by the user. The WTSHM server stores the plurality ofsignals received from the sensor(s) associated with the channel for apredetermined period of time before and after the alert alarm wasinitiated. In the example embodiment, the WTSHM server stores theplurality of signals in the database. The WTSHM server further storesthe plurality of signals with an alert tag for future analysis. In theexample embodiment, the WTSHM server transmits one or more messages to awind tunnel controller which controls the operation of the wind tunnel.The one or more messages include instructions to change the conditionsbeing generated by the wind tunnel. The one or more messages areconfigured to reverse one or more conditions that are affecting aircraftmodel 108 in such a way that an alert alarm was issued. In someembodiments, the one or more messages instruct the wind tunnelcontroller to shut down or deactivate wind tunnel.

In some embodiments, the WTSHM server includes a low-pass or band-passfilter to filter the plurality of signals received from the plurality ofsensors. In these embodiments, the signals are filtered before the WTSHMserver analyzes the plurality of signals. However, when the WTSHM serverstores data in response to a warning alarm or alert alarm, the WTSHMserver stores the unfiltered sensor data.

In some further embodiments, the WTSHM server combines the data from aplurality of channels to compare to the warning and alert thresholds.For example, the WTSHM server may also combine the data from channels A,B, and C to trigger one or more alarms, where the data from each of thechannels is below the warning threshold. In still further embodiments,the WTSHM server may only monitor combinations of channels fortriggering alarms, instead of individual channels.

In some embodiments, the WTSHM server compares the combined channels toa factor of safety. The factor of safety represents a buffer ofoperation before the model is expected to fail. In these embodiments,the WTSHM server may receive the factor of safety from the user. Forexample, the user may determine that the model will fail at a certainpoint. The user sets the factor of safety to allow the WTSHM server toshut down or change operation of the wind tunnel before the model fails.

Described herein are computer systems such as the WTSHM computer devicesand related computer systems. As described herein, all such computersystems include a processor and a memory. However, any processor in acomputer device referred to herein may also refer to one or moreprocessors wherein the processor may be in one computing device or aplurality of computing devices acting in parallel. Additionally, anymemory in a computer device referred to herein may also refer to one ormore memories wherein the memories may be in one computing device or aplurality of computing devices acting in parallel.

As used herein, a processor may include any programmable systemincluding systems using micro-controllers, reduced instruction setcircuits (RISC), application specific integrated circuits (ASICs), logiccircuits, and any other circuit or processor capable of executing thefunctions described herein. The above examples are not intended to limitin any way the definition and/or meaning of the term “processor.”

As used herein, the term “database” may refer to either a body of data,a relational database management system (RDBMS), or to both. As usedherein, a database may include any collection of data includinghierarchical databases, relational databases, flat file databases,object-relational databases, object oriented databases, and any otherstructured collection of records or data that is stored in a computersystem. The above examples are not intended to limit in any way thedefinition and/or meaning of the term database. Examples of RDBMS'sinclude, but are not limited to including, Oracle® Database, MySQL, IBM®DB2, Microsoft® SQL Server, Sybase®, and PostgreSQL. However, anydatabase may be used that enables the systems and methods describedherein. (Oracle is a registered trademark of Oracle Corporation, RedwoodShores, Calif.; IBM is a registered trademark of International BusinessMachines Corporation, Armonk, N.Y.; Microsoft is a registered trademarkof Microsoft Corporation, Redmond, Wash.; and Sybase is a registeredtrademark of Sybase, Dublin, Calif.)

In one embodiment, a computer program is provided, and the program isembodied on a computer readable medium. In an example embodiment, thesystem is executed on a single computer system, without requiring aconnection to a server computer. In a further embodiment, the system isbeing run in a Windows® environment (Windows is a registered trademarkof Microsoft Corporation, Redmond, Wash.). In yet another embodiment,the system is run on a mainframe environment and a UNIX® serverenvironment (UNIX is a registered trademark of X/Open Company Limitedlocated in Reading, Berkshire, United Kingdom). The application isflexible and designed to run in various different environments withoutcompromising any major functionality. In some embodiments, the systemincludes multiple components distributed among a plurality of computingdevices. One or more components may be in the form ofcomputer-executable instructions embodied in a computer-readable medium.

As used herein, an element or step recited in the singular and precededwith the word “a” or “an” should be understood as not excluding pluralelements or steps, unless such exclusion is explicitly recited.Furthermore, references to “example embodiment” or “one embodiment” ofthe present disclosure are not intended to be interpreted as excludingthe existence of additional embodiments that also incorporate therecited features.

As used herein, the terms “software” and “firmware” are interchangeable,and include any computer program stored in memory for execution by aprocessor, including RAM memory, ROM memory, EPROM memory, EEPROMmemory, and non-volatile RAM (NVRAM) memory. The above memory types areexample only, and are thus not limiting as to the types of memory usablefor storage of a computer program.

Furthermore, as used herein, the term “real-time” refers to at least oneof the time of occurrence of the associated events, the time ofmeasurement and collection of predetermined data, the time to processthe data, and the time of a system response to the events and theenvironment. In the embodiments described herein, these activities andevents occur substantially instantaneously.

The systems and processes are not limited to the specific embodimentsdescribed herein. In addition, components of each system and eachprocess can be practiced independent and separate from other componentsand processes described herein. Each component and process also can beused in combination with other assembly packages and processes.

FIG. 1 illustrates a block diagram of an example overview of a windtunnel environment 100 in accordance with one embodiment of the presentdisclosure. Wind tunnel environment 100 includes a wind tunnel 102 thatgenerates a plurality of plurality of conditions 106. The plurality ofconditions 106 simulates various flight conditions that an aircraft mayencounter to determine the effect of these conditions on an aircraft. Inthe example embodiment, wind tunnel 102 is controlled by a wind tunnelcontroller 104, which receives commands from a user (not shown). In someembodiments, wind tunnel 102 provides feedback information to windtunnel controller 104 about the plurality of conditions 106 in windtunnel environment 100.

In the example embodiment, wind tunnel environment 100 also includes anaircraft model 108 that is being tested. In some embodiments, aircraftmodel 108 is a full size aircraft. In other embodiments, aircraft model108 is a scale model of the aircraft to be tested. In still otherembodiments, aircraft model 108 is one or more parts of an aircraft thatare being tested. In the example embodiment, aircraft model 108 issecurely fastened to a mount (not shown) for testing to ensure thataircraft model 108 does not move from the desired location in windtunnel environment 100. An insecurely mounted aircraft model 108 maybreak free from the mount during severe conditions or may allow forvariations to be introduced into in test results, where the variationsare based on interactions between aircraft model 108 and the mount. Inthe example embodiment, plurality of conditions 106 exerts variousforces on aircraft model 108. This plurality of conditions 106 aredesigned to simulate forces or conditions that would or could be exertedon the aircraft represented by aircraft model 108.

In the example embodiment, aircraft model 108 is attached to a pluralityof sensors 110. Each of these sensors 110 measures one or moreattributes of aircraft 108 and the change in these attributes is basedon the plurality of conditions 106 that aircraft model 108 isexperiencing. Plurality of sensors 110 may include, but are not limitedto, signal conditioners and transducers, such as strain gauges, andaccelerometers. Plurality of sensors 110 may measure strain or stress onaircraft model 108, lift, weight, drag, and thrust at various points onaircraft model 108, and other attributes of aircraft model as needed totest aircraft model 108.

In the example embodiment, plurality of sensors 110 provides signals toa wind tunnel structural health monitor (“WTSHM”) computer device 112,also known as a WTSHM server 112. The signals represent the measuredvalues of the attributes associated with each sensor 110.

In some embodiments, WTSHM computer device 112 is in communication withwind tunnel controller 104. In these embodiments, wind tunnel controller104 is configured to transmit information to other computer devices,such as WTSHM computer device 112, about wind tunnel 102 and pluralityof conditions 106 that wind tunnel 102 is generating. In some of theseenvironments, WTSHM computer device 112 is configured to transmitcommands to wind tunnel controller 104 to alter the operation of windtunnel 102, which may change the conditions 106 that are being exertedon aircraft model 108.

FIG. 2 is a simplified block diagram of an example system 200 formonitoring a model 108 (shown in FIG. 1) in wind tunnel environment 100shown in FIG. 1. In the example embodiment, system 200 is used formonitoring conditions 106 in wind tunnel 102 (both shown in FIG. 1),analyzing attributes of aircraft model 108 based on those conditions106, and determining if negative conditions are occurring that may bepotentially dangerous. In addition, system 200 is a monitoring systemthat includes a wind tunnel structural health monitor (WTSHM) computerdevice 210 (also known as a WTSHM server) configured to monitor aircraftmodel 108. As described below in more detail, WTSHM server 210 isconfigured to receive a plurality of signals from a plurality of sensors205. Each sensor 205 of the plurality of sensors 205 is configured tomeasure an attribute of model 108 in wind tunnel 102. The plurality ofsignals represents measurements of the attributes of model 108. WTSHMserver 210 is also configured to store a first threshold and a secondthreshold. The first threshold is between the second threshold andnormal operation. WTSHM server 210 is further configured to analyze theplurality of signals based, at least in part, on the first threshold andthe second threshold, determine that a potentially negative condition isoccurring based on the analysis, and alert a user to the potentiallynegative condition.

In the example embodiment, sensors 205 measure attributes of aircraftmodel 108, similar to sensors 110, shown in FIG. 1. In the exampleembodiment, sensors 205 are communicatively coupled to WTSHM server 210through many interfaces including, but not limited to, at least one of anetwork, such as the Internet, a LAN, a WAN, or an integrated servicesdigital network (ISDN), a dial-up-connection, a digital subscriber line(DSL), a cellular phone connection, a satellite connection, and a cablemodem. Sensor 205 can be any device capable of measuring one or moreattributes of aircraft model 108, such as, but not limited to, strain orstress on aircraft model 108, lift, weight, drag, and thrust at variouspoints on aircraft model 108, and other attributes of aircraft model asneeded to test aircraft model 108.

A database server 215 is communicatively coupled to a database 220 thatstores data. In one embodiment, database 220 is a database that includesthresholds, sensor data, warning data, and alert data. In the exampleembodiment, database 220 is stored remotely from WTSHM server 210. Insome embodiments, database 220 is decentralized. In some embodiments,database 220 is centralized. In the example embodiment, a user canaccess database 220 via a client system (not shown) by logging ontoWTSHM server 210. In some embodiments, database 220 includes a singledatabase having separated sections or partitions or in otherembodiments, database 220 includes multiple databases, each beingseparate from each other. Database 220 stores condition data receivedfrom multiple sensors 205. In addition, database 220 stores thresholds,warning data, alert data, and delay data generated as part of collectingcondition data from multiple sensors 205.

In the example embodiment, WTSHM server 210 receives and analyzes dataabout the operation of wind tunnel 102 and conditions 106 as they affectaircraft model 108. This data could include data from sensors 205,current conditions 106 generated by wind tunnel 102, and otheroperational data that WTSHM server 210 could monitor. Furthermore, WTSHMserver 210 accesses database 220. In some embodiments, WTSHM server 210includes a display unit (not shown) to present the data from wind tunnelenvironment 100 to a user (not shown). In some embodiments, WTSHM server210 is communicatively coupled to the Internet through many interfacesincluding, but not limited to, at least one of a network, such as theInternet, a LAN, a WAN, or an integrated services digital network(ISDN), a dial-up-connection, a digital subscriber line (DSL), acellular phone connection, a satellite connection, and a cable modem.WTSHM server 210 can be any device capable of accessing a network, suchas the Internet, including, but not limited to, a desktop computer, alaptop computer, a personal digital assistant (PDA), a cellular phone, asmartphone, a tablet, a phablet, or other web-based connectableequipment. In some embodiments, WTSHM server 210 includes a low-passfilter (not shown) that filters sensor data.

In the example embodiment, WTSHM server 210 is also in communicationwith wind tunnel controller 225, which may be similar to wind tunnelcontroller 104 shown in FIG. 1. In the example embodiment, wind tunnelcontroller 225 is configured to communicate with and control wind tunnel102. Wind tunnel controller 225 is configured to communicate with WTSHMserver 210 via using the Internet. In some embodiments, wind tunnelcontroller 225 is communicatively coupled to the Internet through manyinterfaces including, but not limited to, at least one of a network,such as the Internet, a LAN, a WAN, or an integrated services digitalnetwork (ISDN), a dial-up-connection, a digital subscriber line (DSL), acellular phone connection, a satellite connection, and a cable modem.Wind tunnel controller 225 can be any device capable of accessing anetwork, such as the Internet, including, but not limited to, a desktopcomputer, a laptop computer, a personal digital assistant (PDA), acellular phone, a smartphone, a tablet, a phablet, or other web-basedconnectable equipment.

FIG. 3 illustrates an example configuration of a client system, inaccordance with one embodiment of the present disclosure. User computerdevice 302 is operated by a user 301. User computer device 302 mayinclude, but is not limited to, wind tunnel controller 225 (shown inFIG. 2). User computer device 302 includes a processor 305 for executinginstructions. In some embodiments, executable instructions are stored ina memory 310. Processor 305 may include one or more processing units(e.g., in a multi-core configuration). Memory area 310 is any deviceallowing information such as executable instructions and/or transactiondata to be stored and retrieved. Memory area 310 may include one or morecomputer readable media.

User computer device 302 also includes at least one media outputcomponent 315 for presenting information to user 301. Media outputcomponent 315 is any component capable of conveying information to user301. In some embodiments, media output component 315 includes an outputadapter (not shown) such as a video adapter and/or an audio adapter. Anoutput adapter is operatively coupled to processor 305 and operativelycoupleable to an output device such as a display device (e.g., a cathoderay tube (CRT), liquid crystal display (LCD), light emitting diode (LED)display, or “electronic ink” display) or an audio output device (e.g., aspeaker or headphones). In some embodiments, media output component 315is configured to present a graphical user interface (e.g., a web browserand/or a client application) to user 301. In some embodiments, usercomputer device 302 includes an input device 320 for receiving inputfrom user 301. Input device 320 may include, for example, a keyboard, apointing device, a mouse, a stylus, a touch sensitive panel (e.g., atouch pad or a touch screen), a gyroscope, an accelerometer, a positiondetector, a biometric input device, and/or an audio input device. Asingle component such as a touch screen may function as both an outputdevice of media output component 315 and input device 320.

User computer device 302 may also include a communication interface 325,communicatively coupled to a remote device such as WTSHM server 210(shown in FIG. 2). Communication interface 325 may also be incommunication with wind tunnel 102 shown in FIG. 1, where user computerdevice 302 provides instructions to and receives data from the windtunnel 102. Communication interface 325 may include, for example, awired or wireless network adapter and/or a wireless data transceiver foruse with a mobile telecommunications network.

Stored in memory area 310 are, for example, computer readableinstructions for providing a user interface to user 301 via media outputcomponent 315 and, optionally, receiving and processing input from inputdevice 320. A user interface may include, among other possibilities, aweb browser and/or a client application. Web browsers enable users, suchas user 301, to display and interact with media and other informationtypically embedded on a web page or a website from WTSHM server 210. Aclient application allows user 301 to interact with, for example, WTSHMserver 210. For example, instructions may be stored by a cloud service,and the output of the execution of the instructions sent to the mediaoutput component 315.

Processor 305 executes computer-executable instructions for implementingaspects of the disclosure. In some embodiments, the processor 305 istransformed into a special purpose microprocessor by executingcomputer-executable instructions or by otherwise being programmed.

FIG. 4 illustrates an example configuration of server system 210 shownin FIG. 2, in accordance with one embodiment of the present disclosure.Server computer device 401 may include, but is not limited to, databaseserver 215, WTSHM server 210, and wind tunnel controller 225 (all shownin FIG. 2). Server computer device 401 also includes a processor 405 forexecuting instructions. Instructions may be stored in a memory area 410.Processor 405 may include one or more processing units (e.g., in amulti-core configuration).

Processor 405 is operatively coupled to a communication interface 415such that server computer device 401 is capable of communicating with aremote device such as another server computer device 401, another WTSHMserver 210, wind tunnel controller 225, client system (not shown), orwind tunnel 102 (shown in FIG. 2). For example, communication interface415 may receive requests from wind tunnel controller 225 via theInternet, as illustrated in FIG. 2.

Processor 405 may also be operatively coupled to a storage device 434.Storage device 434 is any computer-operated hardware suitable forstoring and/or retrieving data, such as, but not limited to, dataassociated with database 220 (shown in FIG. 2). In some embodiments,storage device 434 is integrated in server computer device 401. Forexample, server computer device 401 may include one or more hard diskdrives as storage device 434. In other embodiments, storage device 434is external to server computer device 401 and may be accessed by aplurality of server computer devices 401. For example, storage device434 may include a storage area network (SAN), a network attached storage(NAS) system, and/or multiple storage units such as hard disks and/orsolid state disks in a redundant array of inexpensive disks (RAID)configuration.

In some embodiments, processor 405 is operatively coupled to storagedevice 434 via a storage interface 420. Storage interface 420 is anycomponent capable of providing processor 405 with access to storagedevice 434. Storage interface 420 may include, for example, an AdvancedTechnology Attachment (ATA) adapter, a Serial ATA (SATA) adapter, aSmall Computer System Interface (SCSI) adapter, a RAID controller, a SANadapter, a network adapter, and/or any component providing processor 405with access to storage device 434.

Processor 405 executes computer-executable instructions for implementingaspects of the disclosure. In some embodiments, the processor 405 istransformed into a special purpose microprocessor by executingcomputer-executable instructions or by otherwise being programmed. Forexample, the processor 405 is programmed with the instructions such asillustrated in FIG. 6.

FIG. 5 illustrates an example graph 500 of monitored sensor data fromsystem 200 shown in FIG. 2 during operation of wind tunnel environment100 shown in FIG. 1. Graph 500 includes a y-axis 502 that represents apercentage of normalized alarm limits based on calculated alarmconditions and an x-axis 504 that represents the different channels ofsensor inputs.

In the example embodiment, sensors 205 (shown in FIG. 2) measure aplurality of sensor data about aircraft model 108 (shown in FIG. 1).Sensors 205 transmit the plurality of sensor data to WTSHM server 210(shown in FIG. 2). WTSHM server 210 divides the sensor data up based onsensor type, type of data, location on aircraft model 108, and any otherdivision determined by the user. In some embodiments, sensor data frommore than one sensor 205 may be combined into the same channel.

WTSHM server 210 analyzes and normalizes the sensor data to determinehow close the sensor data is to the alarm limits. Y-axis 502 representsthe normalized alarm limits, shown here as percentages, where 0 isnormal operation and 100% is the level of the highest alarm, shown byline 506. In the example embodiment, sensor data is normalized into apercentage of alert threshold 506 (also known as alarm threshold). Graph500 also includes warning threshold 508, which is at a lower percentage.As shown in FIG. 5, warning threshold 508 changes based on the channel.In other embodiments, alert threshold 506 changes based on the channel.In addition, channel A 510 and channel B 512 may be based on differentdata types; therefore, the same percentage may mean different sensorvalues have been received from the appropriate sensors 205 for thedifferent channels.

As shown in graph 500, channel A 510 is operating at 30%. Since warningthreshold 508 for channel A 510 is 80%, then no alarms are triggered.Channel B 512 is operating at 60%, since warning threshold 508 is 60%,then an alarm is triggered. Channel C 514 and Channel D 516 are alsooperating over their respective warning thresholds 508, but below theiralert threshold 506. Furthermore, Channels C 514 and D 516 are halfwaybetween their respective warning thresholds 508 and the alert threshold506. Channel E 518 exceeds alert threshold 506.

In the example embodiment, alert threshold 506 and warning threshold 508percentages are determined by the user. In this embodiment, the userenters numerical values for alert threshold 506 and warning threshold508 through a computer device such as WTSHM server 210 or a usercomputer device (not shown) in communication with WTSHM server 210. Insome embodiments, alert threshold 506 may be adjusted above or below100%.

FIG. 6 is a flowchart illustrating an example of a process 600 ofmonitoring a model 108 in the wind tunnel environment 100 (both shown inFIG. 1) using system 200 shown in FIG. 2. Process 600 may be implementedby a computing device, for example WTSHM server 210 (shown in FIG. 2).

In the example embodiment, WTSHM server 210 receives 605 a plurality ofsignals from a plurality of sensors 205 (shown in FIG. 2). The pluralityof signals represents data about attributes of aircraft model 108 (shownin FIG. 1). WTSHM server 210 stores 610 a first threshold and a secondthreshold. In the example embodiment, the first threshold is warningthreshold 508 (shown in FIG. 5) and the second threshold is alertthreshold 506 (shown in FIG. 5). In the example embodiment, warningthreshold 508 and alert threshold 506 are set by a user.

In the example embodiment, WTSHM server 210 analyzes 615 the pluralityof signals based on the warning threshold 508 and the alert threshold506. WTSHM server 210 determines 620 that a potentially negativecondition is occurring based on the analysis. WTSHM server 210 alerts625 the user to the potentially negative condition.

In the example embodiment, WTSHM server 210 analyzes 615 the pluralityof signals in comparison to warning threshold 508 and alert threshold506. In the example embodiment, WTSHM server 210 normalizes the sensordata for each channel. In some embodiments, a channel represents asingle sensor. In other embodiments, a channel may represent a pluralityof sensors. For example, WTSHM server 210 may receive sensor data fromthree strain sensors 205 on the left wing of aircraft model 108. WTSHMserver 210 may combine and preprocess the data from the three sensors205 into channel A 510 (shown in FIG. 5). WTSHM server 210 compareschannel A 510 to warning threshold 508 and alert threshold 506. Since inFIG. 5, channel A 510 is at 30%, which is below both thresholds, WTSHMserver 210 does not trigger an alarm and continues to monitor thechannel.

In the case of channel B 512 (shown in FIG. 5), WTSHM server 210determines that the normalized output of channel B 512 is over 60% whichis over warning threshold 508 for channel B 512. WTSHM server 210 alerts625 a user by initiating a short alarm. The alarm may be at least one ofa visual alarm, such as a flash of color on display screen, and a shortaudible alarm, such as a squawk or blat sound.

If WTSHM server 210 determines that warning threshold 508 for channel B512 has been exceeded a predetermined number of times in a predeterminedperiod of time, such as three times in 0.5 seconds, WTSHM server 210initiates a warning alarm. The warning alarm includes at least one of avisual alarm and an audible alarm. In the example embodiment, thepredetermined number and predetermined period of time are set by theuser. WTSHM server 210 stores the plurality of signals received from thesensor(s) 205 associated with channel B 512 for a predetermined periodof time before and after the warning alarm was initiated. Thispredetermined period of time may be stored as delay data. In the someembodiments, WTSHM server 210 received a plurality of signals and theplurality of signals include a large amount of data. To save storagespace, WTSHM server 210 stores the data from the signals in a circularbuffer such that old data is written over after a period of time. Thisperiod of time may be based on the predetermined period of time. Forexample, where WTSHM server 210 stores 5 seconds of data before andafter an alarm was triggered, the circular buffer may contain 13 secondsof data at a time to ensure that that the needed data is stored. In theexample embodiment, WTSHM server 210 stores the plurality of signals indatabase 220 (shown in FIG. 2), where database 220 is located remotelyfrom WTSHM server 210. WTSHM server 210 further stores the plurality ofsignals with a warning tag for future analysis. In some embodiments,WTSHM server 210 also stores the tunnel conditions 106 (shown in FIG.1), the power spectral density of channels, and any bookmarks associatedwith the power spectral density for the time before and after the alarmwas triggered.

WTSHM server 210 also initiates a warning alarm if WTSHM server 210determines that warning threshold 508 has been exceeded by at least halfof the distance between warning threshold 508 and alert threshold 506.This is illustrated in FIG. 5, in both channel C 514 and channel D 516.Channel C 514 is at 80%, which is halfway between warning threshold 508at 60% and alert threshold 506 at 100%. Channel D 516 is at 90% with awarning threshold 508 of 90% and alert threshold 506 at 100%.

When WTSHM server 210 determines that the alert threshold 506 has beenexceeded, as is illustrated in channel E 518 (shown in FIG. 5), WTSHMserver 210 initiates an alert alarm. The alert alarm includes at leastone of a visual alarm and an audible alarm. In the example embodiment,the predetermined number and predetermined period of time are set by theuser. WTSHM server 210 stores the plurality of signals received from thesensor(s) 205 associated with channel E 518 for a predetermined periodof time before and after the alert alarm was initiated. In the exampleembodiment, WTSHM server 210 stores the plurality of signals in database220 (shown in FIG. 2). WTSHM server 210 further stores the plurality ofsignals with an alert tag for future analysis. In the exampleembodiment, WTSHM server 210 transmits one or more messages to windtunnel controller 225 (shown in FIG. 2). The one or more messagesinclude instructions to change the conditions 106 being generated bywind tunnel 102 (both shown in FIG. 1). The one or more messages areconfigured to reverse one or more conditions 106 that are affectingaircraft model 108 in such a way that an alert alarm was issued. In someembodiments, the one or more messages instruct wind tunnel controller225 to shut down or deactivate wind tunnel 102.

In some embodiments, WTSHM server 210 includes a low-pass or band-passfilter to filter the plurality of signals received from the plurality ofsensors 205. In these embodiments, the signals are filtered before WTSHMserver 210 analyzes 615 the plurality of signals. However, when WTSHMserver 210 stores data in response to a warning alarm or alert alarm,WTSHM server 210 stores the unfiltered sensor data.

In some further embodiments, WTSHM server 210 combines the data from aplurality of channels to compare to the warning and alert thresholds.For example, WTSHM server 210 may also combine the data from channels A,B, and C to trigger one or more alarms, where the data from each of thechannels is below the warning threshold. In still further embodiments,WTSHM server 210 may only monitor combinations of channels fortriggering alarms, instead of individual channels.

In some embodiments, WTSHM server 210 compares the combined channels toa factor of safety. The factor of safety represents a buffer ofoperation before the model is expected to fail. In these embodiments,WTSHM server 210 may receive the factor of safety from the user. Forexample, the user may determine that the model will fail at a certainpoint. The user sets the factor of safety to allow WTSHM server 210 toshut down or change operation of the wind tunnel before the model fails.

FIG. 7 is illustrates an example graph 700 of a modified Goodman diagramof monitored sensor data from system 200 shown in FIG. 2 duringoperation of wind tunnel environment 100 shown in FIG. 1. Graph 700includes a y-axis 702 that represents the dynamic state of a channel orsensor input and an x-axis 704 that represents the steady state of thechannel or sensor input.

In the example embodiment, sensors 205 (shown in FIG. 2) measure aplurality of sensor data about aircraft model 108 (shown in FIG. 1). Insome embodiments, sensors 205 include strain gauges or accelerometers.By monitoring one of these sensors 205 over time, WTSHM server 210 isable to calculate the change over time (dt) from the received signal.Using dt, WTSHM server 210 determines dynamic and steady states in thatsignal. WTSHM server 210 maps the dynamic state versus the steady stateon graph 700 using indicator 706. Indicator 706 represents the signalsfrom that sensor 205 in real-time.

WTSHM server 210 also calculates warning threshold 708 and alertthresholds 710 for the signal. In some embodiments, these thresholds 708and 710 are static. In some embodiments, the thresholds 708 and 710change over time based on conditions 106 in wind tunnel 102 (both shownin FIG. 1). For example, if the angle of attack of model 108 changes,WTSHM server 210 may change thresholds 708 and 710.

When indicator 706 exceeds warning threshold 708, WTSHM server 210triggers a warning alarm as described above. When indicator 706 exceedsalert threshold 710, WTSHM server 210 triggers an alert alarm asdescribed above. In some embodiments, WTSHM server 210 stores a bookmarkon graph 700 for each time indicator 706 exceeded at least one of thethresholds 708 and 710. In these embodiments, WTSHM server 210 storesthe bookmark based on the maximum point of indicator 706. In somefurther embodiments, WTSHM server 210 displays each bookmark on graph700 to a user.

FIG. 8 is a diagram 800 of components of one or more example computingdevices that may be used in the system 200 shown in FIG. 2. In someembodiments, computing device 810 is similar to WTSHM server 210 (shownin FIG. 2). Database 820 may be coupled with several separate componentswithin computing device 810, which perform specific tasks. In thisembodiment, database 820 includes thresholds 822, Warning data 824,Alert data 826, and delay data 828. In some embodiments, database 820 issimilar to database 220 (shown in FIG. 2).

Computing device 810 includes the database 820, as well as data storagedevices 830. Computing device 810 also includes a communicationcomponent 840 for receiving 605 a plurality of signals (shown in FIG.6). Computing device 810 also includes an analyzing component 850 foranalyzing 615 the plurality of signals (shown in FIG. 6). Computerdevice 810 further includes a determining component 860 for determining620 that a potentially negative condition is occurring (shown in FIG.6). Moreover, computer device 810 includes an alerting component 870 foralerting 625 a user (shown in FIG. 6). A processing component 880assists with execution of computer-executable instructions associatedwith the system.

As used herein, the term “non-transitory computer-readable media” isintended to be representative of any tangible computer-based deviceimplemented in any method or technology for short-term and long-termstorage of information, such as, computer-readable instructions, datastructures, program modules and sub-modules, or other data in anydevice. Therefore, the methods described herein may be encoded asexecutable instructions embodied in a tangible, non-transitory, computerreadable medium, including, without limitation, a storage device and/ora memory device. Such instructions, when executed by a processor, causethe processor to perform at least a portion of the methods describedherein. Moreover, as used herein, the term “non-transitorycomputer-readable media” includes all tangible, computer-readable media,including, without limitation, non-transitory computer storage devices,including, without limitation, volatile and nonvolatile media, andremovable and non-removable media such as a firmware, physical andvirtual storage, CD-ROMs, DVDs, and any other digital source such as anetwork or the Internet, as well as yet to be developed digital means,with the sole exception being a transitory, propagating signal.

As described above, the implementations described herein relate tosystems and methods for wind tunnel operation, and, more specifically,to monitoring and ensuring the safety of a model in a wind tunnelenvironment. More specifically, a wind tunnel structural health monitor(“WTSHM”) computer device provides a communication interface between aplurality of sensors on a model and computer systems that control a windtunnel. The WTSHM computer device monitors signals from the plurality ofsensors, analyzes the sensor data to determine potential issues withoperation of the wind tunnel, and controls the conditions generated bythe wind tunnel to prevent damage to the model or the wind tunnel.

The above-described methods and systems for wind tunnel operation arecost-effective, secure, and highly reliable. The methods and systemsinclude automatically responding to dangerous conditions, acting onpotentially dangerous conditions faster than a human being, and greatlyincreasing the safety of the operation of a wind tunnel. Accordingly,the methods and systems facilitate safe operation of a wind tunnel in acost-effective and reliable manner.

This written description uses examples to disclose variousimplementations, including the best mode, and also to enable any personskilled in the art to practice the various implementations, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the disclosure is defined by theclaims, and may include other examples that occur to those skilled inthe art. Such other examples are intended to be within the scope of theclaims if they have structural elements that do not differ from theliteral language of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal language of theclaims.

What is claimed is:
 1. A system for monitoring a model in a wind tunnel,said system comprising: a plurality of sensors attached to a model in awind tunnel, wherein each sensor of said plurality of sensors isconfigured to measure an attribute of the model including at least oneof strain, stress, lift, weight, drag, and thrust; and a computingdevice in communication with said plurality of sensors, wherein saidcomputing device includes a processor in communication with a memory,wherein said computing device is programmed to: receive a plurality ofsignals from said plurality of sensors, wherein the plurality of signalsrepresent measurements of the attributes of the model; store a firstthreshold and a second threshold based on normalized alarm limitsassociated with at least one of said plurality of sensors; analyze theplurality of signals based, at least in part, on the first threshold andthe second threshold; determine that the second threshold has beenexceeded; and transmit one or more messages to instruct the wind tunnelto shut down without user interaction.
 2. A system in accordance withclaim 1, wherein said computing device is further programmed to:determine that the first threshold has been exceeded; and initiate ashort alarm, wherein the short alarm is at least one of an audible alarmand a visual alarm.
 3. A system in accordance with claim 1, wherein saidcomputing device is further programmed to: determine that the firstthreshold has been exceeded a predetermined number of times in a firstpredetermined period of time; initiate at least one of an audible alarmand a visible alarm; and store the plurality of signals received for asecond predetermined period of time before and after the alarm wasinitiated, wherein the stored plurality of signals is associated with awarning tag.
 4. A system in accordance with claim 1, wherein the firstthreshold is a distance from the second threshold, and wherein saidcomputing device is further programmed to: determine that the firstthreshold has been exceeded by a predetermined portion of the distancebetween the first threshold and the second threshold; initiate at leastone of an audible alarm and a visible alarm; and store the plurality ofsignals received for a second predetermined period of time before andafter the alarm was initiated, wherein the stored plurality of signalsis associated with a warning tag.
 5. A system in accordance with claim1, wherein said computing device is further programmed to: initiate atleast one of an audible alarm and a visible alarm; store the pluralityof signals received for a second predetermined period of time before andafter the alarm was initiated, wherein the stored plurality of signalsare associated with an alert tag; determine one or more changes toconditions in the wind tunnel so that at least the second threshold isno longer exceeded; and transmit one or more messages to the wind tunnelto implement the one or more changes to the conditions in the windtunnel without user interaction, so that at least the second thresholdis no longer exceeded.
 6. A system in accordance with claim 1, whereinsaid computing device is further programmed to store the plurality ofsignals received for a second predetermined period of time before andafter the alarm was initiated, wherein the stored plurality of signalsare associated with an alert tag.
 7. A system in accordance with claim1, wherein said computing device is further programmed to store thefirst threshold and the second threshold based on one or more userinputs.
 8. A system in accordance with claim 1, wherein said computingdevice is further programmed to: receive the plurality of signals in aplurality of channels, wherein each channel of the plurality of channelsincludes signals from one or more sensors of the plurality of sensors;and store a first threshold and a second threshold associated with eachchannel of the plurality of channels.
 9. A system in accordance withclaim 1, wherein the computing device is further programmed to:calculate a steady state for one sensor of the plurality of sensors;calculate a dynamic stat for the one sensor; continually compare thesteady state to the dynamic state; and determine that an operatingcondition where damage may occur to at least one of the model and thewind tunnel is occurring based on the comparison.
 10. A wind tunnelstructural health monitor (WTSHM) computer device for monitoring a modelin a wind tunnel, said WTSHM computer device comprising a processor incommunication with a memory, said processor programmed to: receive aplurality of signals from a plurality of sensors, wherein each sensor ofthe plurality of sensors is configured to measure an attribute of amodel in the wind tunnel, wherein the plurality of signals representmeasurements of the attributes of the model including at least one ofstrain, stress, lift, weight, drag, and thrust; store a first thresholdand a second threshold based on normalized alarm limits associated withat least one of the plurality of sensors; analyze the plurality ofsignals based, at least in part, on the first threshold and the secondthreshold; determine that the second threshold has been exceeded;determine one or more changes to operating conditions in the wind tunnelwithout making changes to the model so that at least the secondthreshold is no longer exceeded; and transmit one or more messages tothe wind tunnel to implement the one or more changes to the operatingconditions in the wind tunnel without user interaction, so that at leastthe second threshold is no longer exceeded.
 11. A WTSHM computer devicein accordance with claim 10, wherein the processor is further programmedto: determine that the first threshold has been exceeded; and initiate ashort alarm, wherein the short alarm is at least one of an audible alarmand a visual alarm.
 12. A WTSHM computer device in accordance with claim10, wherein the processor is further programmed to: determine that thefirst threshold has been exceeded a predetermined number of times in afirst predetermined period of time; initiate at least one of an audiblealarm and a visible alarm; and store the plurality of signals receivedfor a second predetermined period of time before and after the alarm wasinitiated, wherein the stored plurality of signals is associated with awarning tag.
 13. A WTSHM computer device in accordance with claim 10,wherein the first threshold is a distance from the second threshold, andwherein the processor is further programmed to: determine that the firstthreshold has been exceeded by a predetermined portion of the distancebetween the first threshold and the second threshold; initiate at leastone of an audible alarm and a visible alarm; and store the plurality ofsignals received for a second predetermined period of time before andafter the alarm was initiated, wherein the stored plurality of signalsis associated with a warning tag.
 14. A WTSHM computer device inaccordance with claim 10, wherein the processor is further programmedto: initiate at least one of an audible alarm and a visible alarm; andstore the plurality of signals received for a second predeterminedperiod of time before and after the alarm was initiated, wherein thestored plurality of signals are associated with an alert tag.
 15. AWTSHM computer device in accordance with claim 10, wherein the processoris further programmed to: initiate at least one of an audible alarm anda visible alarm; store the plurality of signals received for a secondpredetermined period of time before and after the alarm was initiated,wherein the stored plurality of signals are associated with an alerttag; and transmit one or more messages to instruct the wind tunnel toshut down without user interaction.
 16. A WTSHM computer device inaccordance with claim 10, wherein the processor is further programmedto: receive the plurality of signals in a plurality of channels, whereineach channel of the plurality of channels includes signals from one ormore sensors of the plurality of sensors; and store a first thresholdand a second threshold associated with each channel of the plurality ofchannels.
 17. A method for monitoring a model in a wind tunnel, saidmethod implemented using a wind tunnel structural health monitor (WTSHM)computer device, said WTSHM computer device comprising a processor incommunication with a memory, said method comprising: receiving aplurality of signals from a plurality of sensors, wherein each sensor ofthe plurality of sensors is configured to measure an attribute of amodel in the wind tunnel, wherein the plurality of signals representmeasurements of the attributes of the model including at least one ofstrain, stress, lift, weight, drag, and thrust; storing a firstthreshold and a second threshold based on normalized alarm limitsassociated with at least one of the plurality of sensors; analyzing theplurality of signals based, at least in part, on the first threshold andthe second threshold; determining that the second threshold has beenexceeded; determining one or more changes to operating conditions in thewind tunnel without making changes to the model so that at least thesecond threshold is no longer exceeded; and transmitting one or moremessages to the wind tunnel to implement the one or more changes to theoperating conditions in the wind tunnel without user interaction, sothat at least the second threshold is no longer exceeded.
 18. A methodin accordance with claim 17 further comprising: determining that thefirst threshold has been exceeded a predetermined number of times in afirst predetermined period of time; initiating at least one of anaudible alarm and a visible alarm; and storing, in the memory, theplurality of signals received for a second predetermined period of timebefore and after the alarm was initiated, wherein the stored pluralityof signals are associated with a warning tag.
 19. A method in accordancewith claim 17, wherein the first threshold is a distance from the secondthreshold, and wherein the method further comprises: determining thatthe first threshold has been exceeded by a predetermined portion of thedistance between the first threshold and the second threshold;initiating at least one of an audible alarm and a visible alarm; andstoring the plurality of signals received for a second predeterminedperiod of time before and after the alarm was initiated, wherein thestored plurality of signals is associated with a warning tag.
 20. Amethod in accordance with claim 17 further comprising: initiating atleast one of an audible alarm and a visible alarm; and storing theplurality of signals received for a second predetermined period of timebefore and after the alarm was initiated, wherein the stored pluralityof signals are associated with an alert tag.